This invention relates to saws and more particularly relates to reciprocating saws that are used typically for rough cutting applications and relates to clamps for clamping the blade in the saw.
Reciprocating saws are used by variety of tradesmen such as plumbers, electricians and carpenters for both remodeling and new construction. Many of the applications require the saw to be used in confined locations that restrict the maneuverability of the saw. Conventionally such saws have an elongated, integral housing and have the blade fixed for reciprocation in a single plane. One known way for increasing the maneuverability of the saw is to make the blade clamp and drive rotatable about the axis of reciprocation of the output shaft of the saw. As a result the blade can be rotated into any angular orientation about the axis of reciprocation permitting the blade to more easily positioned for cutting in a corner or adjacent to the vertex of an angular workpiece. Examples of such saws are disclosed in U.S. Pat. No. 5,193,281 and PCT application WO94/00264. These approaches requiring the drive shaft to be rotatable about its axis of reciprocation are complex and have not proved to be practical.
Another approach is to make the blade holder capable of receiving the blade in a plurality of cutting planes parallel to the axis of reciprocation. An example of this approach is disclosed in European patent application 0,072,282. The clamp has a plate connected to the output shaft with screws. To change blade orientation between 90.degree. offset cutting planes requires removing the plates by unscrewing the screws, changing the blade orientation, rotating the plate 180.degree. and then reattaching the plate to the shaft. While simpler and more practical, this approach still fails to achieve the desired level of simplicity.
A further strong design preference in power tools today is to develop keyless chucks and clamps which do not require tools for clamping and unclamping an accessory bit or blade in the power tool. A keyless clamp is desirable because it is normally easier to use and can be used without auxiliary tools which frequently become misplaced or lost. As used herein, a keyless clamp means a clamp that can be opened and closed without the aid of an auxiliary tool by manual adjustment of the clamp segments.